Data storage devices generally operate to store and retrieve data in a fast and efficient manner. Some storage devices utilize a semiconductor array of solid-state memory cells to store individual bits of data. Such memory cells can be volatile or non-volatile.
Volatile memory cells generally retain data stored in memory only so long as power continues to be supplied to the device, while non-volatile memory cells generally retain data storage in memory even in the absence of the application of power.
Some non-volatile memory cell constructions include a resistive sense memory element that can be programmed to different resistance states, such as a high resistance or a low resistance. Different logical states are assigned to the different resistance states of the cell, such as a logical 1 to the low resistance state and a logical 0 to the high resistance state (or 00, 01, 10, 11 in some multi-bit designs). Such elements can be bipolar in that write currents to program the respective states are applied in opposite directions through the cell.
A switching device, such as a metal oxide semiconductor field effect transistor (MOSFET), may be incorporated into the memory cell to accommodate the bipolar memory element write currents. Such integrated switching devices can be relatively large with respect to the memory elements, and therefore the size of the switching devices can limit the ability to achieve higher data areal densities in a memory array.